Coventry student’s research aids in development of heat-sensitive materials

KINGSTON, R.I. -- September 8, 2005 -- Coventry resident Ashley Mills decided to major in chemistry at the University of Rhode Island partly because it’s “a field that is constantly changing.” She’s been conducting research on some of those changes for the last two years, helping URI researchers learn more about a polymer they developed that changes color at different temperatures and has applications in dozens of products.

Imagine a milk carton that changes color when the milk has been at room temperature for too long; or a cooking pot that changes color to indicate it’s too hot to touch; or road signs that change color indicating icy conditions. A polymer that can potentially do all these things was developed by URI researcher Brett Lucht and his colleagues in 2002, and for the last two years Mills has been helping the professors learn more about it.

“Basically, we’re trying to determine its different properties,” said the 20-year-old junior. “By altering the polymer, we’re trying to discern why it changes color, how to make it change at certain temperatures, and how to get it to change to particular colors.”

So far, the polymer changes from red to yellow between 50 and 100 degrees centigrade. “By changing the molecular structure of the polymer, we’re able to change its color and change the temperature at which the color change occurs,” Mills said.

In a typical day in the lab, she makes a variety of samples of the polymer and uses reflection spectroscopy and differential scanning calorimetry (DSC) to test them.

“Different colors reflect light at different wave lengths, so reflection spectroscopy uses a light probe to measure the light reflected off the polymer to tell us exactly when the color change occurs,” said Mills, a 2003 graduate of Coventry High School. “The DSC measures the amount of heat it takes to change the polymer color.”

Mills will continue her research on the heat-sensitive polymer for the coming school year. After graduation in 2007, she plans to pursue a graduate degree.

“Hopefully I’ll get my doctorate and get into forensic science or some other lab work. And maybe eventually I’ll teach chemistry, too,” she said.